Push rod mechanism



March 7, 1961 J. H. WILLIAMS PUSH ROD MECHANISM Filed March 11, 1959 2 Sheets-Sheet 1 HII INVENTOR.

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March 7, 1961 J- H. WILLIAMS 2,973,664

PUSH ROD MECHANISM Filed March 11, 1959 2 Sheets-Sheet 2 United States Patent O 2,973,664 rusn ROD MECHANISM John H. Williams, Barrington, Ill., assignor to Oak 2 Manufacturing Co., a corporation of Delaware Filed Mar. 11,1959, Ser. No. 798,625 6 Claims. 74-483) This invention relates to a push rod mechanism and particularly to a mechanism having a plurality of push rods with means for locking the push' rods to an in position and for unlocking said push rods to an out position.

Push rod mechanism for operating switches are well known and are widely used. As example of such mechanism is that disclosed in United States Patent No. 2,289,- 513, issued July 14, 1942. In the construction disclosed in said patent, a latch bar cooperating with a plurality of push rods is provided. Means are provided whereby by coil spring 30 disposed around spaced fingers 31 with-- in cutout 32 in head end 26 of the latch bar. Coil spring 30 cooperates with the inside face of end plate 13 for biasing the latch bar.

Latch bar 25 is slotted to provide a plurality of rectangular portions 35 extending from the bottom part of the latch bar toward the inside face of top plate 10. The spacing between rectangular portions 35 is such as to provide one rectangular portion 35 and an adjacent slot 36 between a pair of adjacent push rods 20. Latch bar 25 may be so positioned as to have an edge of rectangular portion 35 of a latch bar engage the side of a shoulder 21 of a push rod in the normal locked position of the push rod. From this position, the latch bar and each rectangular portion 35 may be pushed or moved along the bar length to an unlocking position against the bias of spring 30 so that each rectangular projecting portion 35 moves away from its cooperating push rod shoulder. This cooperation between portion 35 and a shoulder is not too important since finger 36 on latch bar is provided to cooperate with end plate a push rod, normally biased to an out" position, may be locked to an in position. Unlocking means are provided for releasing the previously locked push rods.

This invention provides a simple and effective mechanism for accomplishing the locking and release of the push rods in a latch bar type of mechanism.

In order that the invention may be fully understood, it will'now be explained in connection with the drawings wherein Figure 1 is. a side elevation of :the'mechanism embodying the present invention.

Figures 2 and 3 are end views from the adjacent ends of the structure illustrated in Figure 1.

Figure 4 is a section on line 4-4 of Figure 1.

Figure 5 is a detail of'part of the mechanism illustrated in Figure 1 showing the unlocking push rod in an in position.

Figure '6 is a section on line 6-6 of Figure 1;

Figures 7 and 8 are transverse sections of the mechanism illustrating the out and in positions, respectively, of a push rod.

Figure 9 is an exploded view of the latch bar and spring strip normally attached thereto.

Figures 9a and 10 are details of the portions of the spring carried by the latch bar for locking a push rod.

The mechanism generally comprises front plate 10 andrear plate 11 maintained rigidly in spaced parallel relation by end plates 12 and 13. Plates 10 and 11 have their edges bent to form small flanges for strengthening the plates.

Plates 10 and 11 are provided with registering slots 15 and 16 extending transversely across the plates. Each pair of registering slots in the front and rear plates cooperate to accommodate a slidably mounted push rod 20. Push rod 20 has shoulders 21 which are disposed between front plate 10 and rear plate 11. Coil spring 23 is disposed around the body of push rod 20 between rear plate 11 and shoulders 21. The coil spring biases each push rod to an out position where the shoulders of the push rod rest against the inside face of front plate 10.

Slidably disposed in end plates 12 and 13 is latch bar generally indicated by 25. Latch bar 25 has head end 26 slidably disposed in slot 27 in end plate 13 and has free end 28 slidably disposed in slot 29 in end plate 1,2. Latch bar 25 is biased to a normal locking position 12 for stopping the latch bar.

' Latch bar 25 is provided with-a plurality of spring metal locking fingers 39. Springlocking fingers '39 are conveniently disposed on spring body strip 40 riveted to latch bar 35 along the bottom portion of the latch bar at the side thereof. Spring locking fingers 39 are provided with bent cam edge 41 adjacent shoulder 21 of the push rods. Each spring locking finger 39 is also provided with stop portion 4 Each spring locking finger 39 is so shaped as to permit shoulder 21 of a push rod to slide underneath a spring finger, urging the spring finger outwardly away from the shoulder and permitting the shoulder to move beyond stop portion 43. Thus, each push rod 20 may be locked to an in position by moving spring locking portion 39 laterally of the latch bar outwardly away from a push rod shoulder.

It is clear that any desired push rod may be deprived of its locking function by removing the corresponding spring locking portion.

In order to release any of the locked push rods, unlocking push rod 50 is provided. Push rod 50 is generally similar to push rods 20. However, push rod 50 has shoulder portion 51 similar to shoulder 21 of rods 20 which cooperates with cam shaped edge 52 upon head end 26 of latch bar 25. Cam shaped portion 52 is so shaped that inward movement of push rod 50 will cause latch bar 25 to be moved against its spring bias. This movement of the latch bar is sufiicient to clear each spring portion 39 from any shoulder 21 of a push rod which may be in the locked position.

What is claimed is:

1. A push rod mechanism comprising at least one elongated plate having a plurality of laterally disposed transverse slots arranged in parallel relation, a push rod for each slot, spring means for biasing each push rod to an out position from which position it may be moved along its length to an in position, a latch bar, means for supporting said latch bar to extend across the side edges of the push rods, said latch bar being movable along its own length, means for biasing said latch bar to a normal locking posit-ion from which position said latch bar is movable to an unlocking position, said latch bar having a projecting portion which is at all times disposed between two adjacent push rods, a generally fiat spring locking finger carried by said latch bar at the side thereof for cooperation with each push rod, said spring locking finger being biased to lie against said latch bar projecting portion and being deflectable lateral- 'ly away from said latch bar projecting portion, means apnoea for latching a push rod to an in position, said means cooperating with the spring locking finger for springing said finger outwardly away from the latch bar projecting portion upon inward movement of said'push rod and thereafter releasing said spring locking finger to return to its normal position to a locking condition-and means for moving said latch bar to an unlocking position so that a push rod is clear of its cooperatinglocking finger permitting the rod to return to a normal out position.

2. The construction according to claim 1 wherein said means on a push rod cooperating with a spring locking finger comprises a shoulder portion for cooperation with a spring locking finger, said shoulder being movable with the push rod to lock againsta locking finger for maintaining the push rod in against its bias.

3. A push rod mechanism comprising front and-rear support plates, means for maintaining the same in opposed face to face parallel relation, said support plates having transverse slots therethrough so that said two support plates have a series of slot pairs, a push rod for each pair of slots, said push rod having portions extend ing through the slots and having a shoulder portion between said plates, said shoulder portion normally lying against the inside face of the front plate, a coil spring disposed around said push rod and extending between the shoulder and the rear plate for biasing said push rod to an out position from which position said push rod is manually movable to an in position, a flat latch bar disposed between said plates and extending longitudinally thereof, the plane of said latch bar being generally normal to the parallel planes of said plates, said latch bar having slots extending inwardly from the edge of the latch bar adjacent the front plate, a latch bar slot-being located so that the shoulder of a push rod is always clear of said latch bar, a flat spring rigidly attached to said latch bar along the portion thereof ad.- jacent the rear plate, fingers extending toward the front plate, each spring locking finger lying against a latch bar portion adjacent a slot, a spring locking finger however having a part overlying a latch barslot, each spring locking finger being wide enough alongthe length of the -latch bar so that in one latch bar position the push rod shoulder can physically engage a spring locking finger and in another latch bar position each spring locking finger is'clear of said fiat spring having spring locking a push rod shoulder so that the push rod shoulder is free in the latch bar slot, means for biasing said latch bar to said one position, each push rod shoulder being sufficiently long to extend into the latch bar slots and cooperating with a spring locking finger, each spring locking finger being shaped so that a push rod can be moved to an in position to :springsaid locking finger away from the latch bar and perrnit said push rod shoulder to clear the locking finger, each springlocking finger being shaped so thata push rod shoulder will be caught when the push rod is. in," said spring locking finger moving to its normal position against the latch bar and means for moving said latch-bar to'said other position to release any in push rods.

4. The construction according to claim 3 wherein the means for moving a latch bar comprises an additional push rod having a shoulder similar to the other push 1 rodsfsaid latch bar having a cam surface cooperating with said additional push rod shoulder so that when said additional push rod is moved-toan in position, said latch bar is moved from its biased to its other position.

5. The construction according to claim 4 wherein said latch bar has means'for defining the biased position of said latch bar, said biased position being selected so that the shoulder of each push rod lies in that portion of the slot of a latch bar which is covered by the spring finger. I

6. The construction accordingto claim 5 wherein each spring finger is shaped so that the cooperating push rod shoulder can deflect the spring finger laterally as the push rod moves inwardly and'wherein said spring finger has a notched portion for accommodating the shoulder 1 when the push-rod is fully ,in thereby permitting said spring finger. to return to its normal position against the latch bar.

References Cited in the file of this patent UNITED STATES PATENTS 2,289,513 Mastney July 14,1945.

2,311,322 Zimmerman et al Feb. 16, 1943 2,318,554 Raney May 4, 1943 7 2,857,781 Williams Oct. 28, 1958 FOREIGN PATENTS P 897,775 Germany Nov. 23, 1953 

